Ice-filled cold storage means for repeated freezing and melting

ABSTRACT

Ice-filled cold storage means for the repeated freezing and, accompanied by the cooling of air or a cooling fluid, melting of the ice, with an elastic sleeve ( 2 ) for an ice supply, which is kept by a substantially dimensionally stable jacket ( 3 ) under close heat transfer contact at the location of an air or fluid guide and which is set up for moving air to be cooled or dehumidified or a cooling fluid past the ice supply.

This application is a §371 U.S. National Phase application which basespriority on International Application No. PCT/DE99/01405, filed May 10,1999, which in turn bases priority on German Application No. DE 298 08895.9, filed May 11, 1998.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a ice-filled cold storage means for repeat edfreezing and melting according to the preamble of the main claim. Coldstorage means are e.g. used in refrigeration technology moreparticularly for vehicle cooling and air conditioning.

2. Description of the Prior Art

Vehicles are cooled and air conditioned, because in vehicles the airtemperature and humidity can reach values which can impair theconcentration of the vehicle driver, which can have an effect on thesafety of road traffic. Another reason for air treatment is the comfortof the vehicle occupants and the requirements concerning transportedgoods.

Vehicles which are not in operation can normally not be cooled or airconditioned, because the cooling and air conditioning system is normallyjointly supplied by the vehicle drive. Thus, particularly in the sun,such vehicles can be subject to considerable heating.

The heating effect is particularly critical if the vehicle is occupiedand the engine cannot or may not be operated, so that the airconditioning and cooling system cannot function, because the drive isnot available for it, which is e.g. the case with vehicles, on ferries,trucks and border crossings, in stop and go traffic or in the case ofsmog.

The problem of the invention is to provide for such cases a cold storagemeans. This makes it unnecessary to have a separate drive for cooling orair conditions systems and cooling and air conditioning can take placeindependently of the operation of the drive engine.

Ice is proposed for the storage means operation, particularly in thecase of vehicles. Ice is produced from water or an aqueous solution ormixture (hereinafter merely referred to as water to facilitateunderstanding).

Among all standard single-component liquids water has both the highestspecific heat capacity and the highest specific melting heat. Inaddition, water is inexpensive and safe. This makes water a suitablestorage medium. Due to the high melting heat cold storage by ice (latentenergy) is far superior to the storage of cold water (sensible energy)due to the lower volume or weight.

However, also in the ice range water has an abnormal behaviour comparedwith most other substances. In particular the volume rises in the caseof ice formation and then decreases again on undercooling or subcoolingthe ice. If this volume change cannot be compensated by constructionalmeasures (e.g. by a buffer volume), containers in which ice is producedcould burst as a result of the ice pressure.

For weight and space reasons the cold storage means should also be smalland light. This requires the complete freezing of the water to ice withthe consequence that the volume change on freezing and melting isabsorbed in an operationally safe manner.

SUMMARY OF THE INVENTION

According to the invention these limiting conditions have been satisfiedby a cold storage means having the features of the main claim. Thesubclaims give advantageous embodiments of the invention.

The cooling system in the vehicle and which is supplied by the vehicledrive, during operation and within the scope of the available capacitytakes over the cooling of the vehicle interior and/or can additionallysupply the cold storage means (“charging operation”). Part or all thecooling capacity is used for ice formation (if the water of the coldstorage means is heated the water is firstly cooled to the freezingpoint).

As a function of the regulatability of the cooling system, followingfreezing, the ice is further cooled (“undercooling”) or the cold supplyof the cold storage means is interrupted. In any case the volume of theice has at least temporarily increased.

As soon as the cold storage means is used for air cooling purposes(“discharging operation”), a heat flow to the ice heats and/or melts thelatter. The ice is again transformed into water, which is optionallystill warmed. This discharging process is also associated with volumechanges.

As a result of the volume changes in charging and discharging operationadditional drive forces come into action due to the changed specificvolumes, which in particular during discharging operation lead to themelted ice floating in the water. If the cold storage means iscompletely discharged during each operating cycle (the ice beingcompletely melted), when a charging operation takes place again alwaysthe same starting conditions apply under which the ice is initiallyformed at the coldest point of the cold storage means. This type ofcharging operation is reproducible and can be constructionallycomparatively easily controlled.

However, it is difficult to operate the cold storage means if the icehas not yet completely melted before the cold storage means is againsupplied from the cooling system (“partial discharging”). As a result ofthe buoyancy forces of the ice and optionally as a result of forces fromthe vehicle operation ice from a partially discharged storage means cancollect at points where it leads to additional problems in the case of arepeated charging operation. With energy release through the cooling orrefrigerating machine, accumulated ice can locally possibly lead to anincreased volume and therefore increased pressure, which is anadditional burden on the container construction.

The partial discharge problem can be counteracted in that the cooling iscontrolled in such a way that there must always be a complete dischargebefore repeated freezing is allowed. However, this represents a waste ofenergy and is usually not possible or sensible for time reasons alone,e.g. in the case of motor vehicles.

Thus, the cold storage means of a vehicle must be “cycle-proof”, i.e.all charging and discharging states, including the partial discharge,must be operationally safe over a random number of cycles.

The invention achieves the desired objective with a cold storage meanshaving the features of the main claim, in which the container in whichthe ice is formed and melted is constructed elastically. Advantageously,there is in particular an elastic sleeve, which by means of an external,dimensionally stable jacket is held in fixed manner in close heattransfer contact with air or some other cooling fluid which is to becooled and/or dehumidified. On the jacket can be provided ribs or ribsegments, depressions or prongs for the purpose of increasing the heattransfer surface.

A preferred embodiment proposes a substantially cross-sectionallycircular, elastic sleeve being housed in a surrounding circular,dimensionally stable jacket, in which a circular portion is in the formof a slot in order to permit a volume change to the sleeve in the caseof jacket deformation.

It is also proposed that the jacket be constructed with more than onerecess and for clamping members to be provided for holding together thesegments. The jacket can also be formed entirely by clamping members. Itis also proposed that a pipe for the cooling or refrigerating fluidsupply be in heat transfer contact with the inside or outside of thejacket. With an arrangement of the cooling fluid pipe in the sleeve,said sleeve can be connected to the pipe in such a way that the sleeveis connected tightly and permanently to the pipe at its inlet and outlet(e.g. by bonding pipe and sleeve).

The sleeve can also have a cushion shape with a pocket for receiving apipe. A cushion-like sleeve can embrace the cooling fluid pipe in such away that said cushion is so placed around the pipe that the latter islocated in “folds” of the cushion. In this case there is no need forfixing, e.g. by bonding. Through a subdivision of the sleeve intochambers smaller individual volumes are created in which ice is in eachcase retained. These small volumes can e.g. be represented bylongitudinal and/or transverse seams of the cushion- like sleeve. Thecushion-like sleeve can be subdivided into small volumes byvulcanization, welding, bonding or sewing.

It is also possible to introduce into the sleeve part of the fluid orsome other fluid in the form of capsules. As a result of the heaping ofthe capsules a floating thereof is virtually prevented, so that therecan be no pronounced floating of melting ice as a result of buoyancy.This gives a largely homogeneous structure in the sleeve.

The capsules can be filled with a freezable fluid and a specific capsulevolume can remain fluid-free. It is appropriately an air volume, whichis compressed on freezing the fluid an d leads to no or only a slightcapsule volume rise. Thus, the high ice pressure is absorbed by acompressible gas.

A decision must e.g. be reached as to whether the capsules and thesleeve contain the same or different fluids. The fluid in the sleeve canbe a substance, which at a different temperature freezes or remainsliquid. The sleeve can also contain a freezing fluid, whereas thecapsules contain a non-freezing fluid. This is in particular the case ifthe capsules contain a compressible substance (a gas, e.g. air). Thisgas would absorb the ice pressure of the surrounding, freezing fluid andchange its volume.

Each of these possibilities has its own specific fields of use, whichare in particular dependent on the geometry and desired time componentof the cold storage means. The individual capsules are advantageouslyconstructed in elastic manner so as to restore their shape, but therecan also be an element, e.g. a spring in the capsules, which compensatesthe volume change and restores the capsule shape. Another possibilityfor restoring the capsule shape is a volume change-compensating gasvolume in the capsules. Finally capsules having a lens and/or dumbbellshape is proposed.

Further features and advantages of the invention can be gathered from afollowing description of a preferred embodiment and the attacheddrawings, wherein show:

DESCRIPTION OF THE DRAWINGS

FIG. 1 An elastic sleeve 2 surrounded by a dimensionally stable jacket3, the cooling fluid pipe or pipes 4 being attached externally to thesleeve 2.

FIG. 2 A representation corresponding to FIG. 1 with a cooling fluidpipe 4 placed centrally through the water to be frozen.

FIG. 3 A subdivision of the jacket into several segments.

FIG. 4 A further construction in which the jacket is formed by clampingstraps 5.

FIG. 5 An elastic sleeve surrounded by a dimensionally stable jacket,the cooling fluid pipe or pipes being attached within the jacket.

FIG. 6 An elastic sleeve.

FIG. 7 An elastic sleeve as in FIG. 6, which is subdivided into smallersingle volumes by “tying off” by constriction.

FIG. 8 A dumbbell-shaped capsule 7.

FIG. 9 A cushion-like, elastic sleeve, which is subdivided by punctiformconnections 8 of the two surfaces.

FIG. 10 A cushion-like, elastic sleeve, which is subdivided intochambers by longitudinal and/or transverse seams 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIG. 1 an elastic sleeve 2 is surrounded by a dimensionally stablejacket 3, so that a rigid, dimensionally stable container is obtained inwhich the water is frozen and as ice can be melted, the volume change attypical operating temperatures being absorbed by an elastic inner layerand a slight shape change of the outer layer. As a result of the thininner layer of sleeve 2 a heat transfer is readily possible. As a resultof the extension of the sleeve 2 the full-surface, good thermal contactis further improved, because the intimacy of the connection isincreased.

Heat removal takes place by cooling fluid-filled pipes 4, in which thecooling fluid is evaporated so as to in this way make available thenecessary cooling capacity. These pipes 4 can be positioned externallyas in FIG. 1 or internally as in FIGS. 2 and 5. The pipes 4 can be inheat transfer contact with the sleeve 2.

Preference is given to a construction in which the sleeve 2 isconstructed as a “cushion”, e.g. as a long sleeve 2 subdivided bylongitudinal and transverse seams 9. The sleeve 2 is placed around thepipe or pipes and can then be inserted in the jacket. This avoids seamsor joints between the sleeve 2 and the pipe 4, which increasesoperational safety and reliability.

A further construction can involve clamping straps 5 surrounding thesleeve using elastic clamping straps or, if the sleeve 2 is veryelastic, solid clamping straps 5, which are not elastic and in thelatter case the volume change can be absorbed in the slots between theclamping straps by expansion of the sleeve. For increasing a clearlydefined geometry it is possible to introduce further rigid “inserts” inthe form of rods or bars between the sleeve and the clamping straps,which define the geometry of the cold storage means.

The sleeve 2 shown in FIG. 6 and subdivided by tying off with tying offdevices 6 can e.g. be formed by an elongated hose and subdivided withthe aid of metal clips, strings, vulcanization, etc., so that individualchambers are formed, which reduce the effects of buoyancy of frozen icein unfrozen water to a smaller volume and consequently “homogenize” theeffects of buoyancy.

The undesired “asymmetrical freezing out” of the ice, which leads to acompaction of ice at upper locations, is consequently subdivided oversmaller areas and therefore also small, absolute length changes of theice volumes.

It is also possible to place in the sleeve part of the fluid or someother fluid in the form of fluid-filled capsules 7. FIG. 10 is anexample of a dumbbell-shaped capsule, but obviously spherical orlenticular capsules are also possible.

However, as a result of the dumbbell-shaped capsule 7 a particularlylarge surface area is obtained, which leaves sufficient elasticity inthe capsule wall to compensate volume changes.

It is proposed that the capsules also be filled with a freezable fluidand a specific capsule volume remains fluid-free. It is appropriately anair volume, which is compressed on freezing the fluid and only allowsthe capsule volume to rise slightly or not at all. Thus, the high icepressure is absorbed by a compressible gas, e.g. air.

Usable freezing point-reducing substances are organic salts such asacetate, formate, propionate, as well as glycol, sugar, fructose,ammonia, potash or a potash compound, glycerol, calcium chloride,magnesium chloride, common salt, ethanol, isopropanol or methanol.

For the particular application it is left to individual choice whetherthe same or different fluids are used in the capsules and sleeve. Thefluid in the sleeve can be a substance, which either freezes at anothertemperature or is intended to remain liquid.

The sleeve can also contain a freezing fluid, whereas the capsulescontain a non-freezing fluid. This is particularly the case if thecapsules contain a compressible substance, e.g. a gas such as air. Thisgas absorbs the ice pressure of the surrounding freezing fluid andchanges the volume thereof.

As the capsules are intended to reassume their original shape followinga volume change, it is appropriate to construct the capsules in such away that there can be no permanent deformation. This risk moreparticularly exists with spherical capsules, which can be “dented” by anexternal pressure acting on all sides and consequently may not reassumetheir original shape. Thus, a lenticular or dumbbell-shaped capsuledesign is more appropriate. It is unimportant whether use is made of afreezing liquid (expansion) or a non-freezing liquid.

In order to increase the resiliency of the capsules, it is also possibleto introduce into the capsules small springs (expanding springs, helicalsprings, etc.) or a compressible material, e.g. foam, rubber, etc. or tointroduce same together with the fluid and optionally a gas cushion.Lenticular capsules are particularly suitable for this purpose.

It is finally also proposed that the sleeves 2 in cushion form be givenlarger dimensions and the cushions surround the cooling fluid pipe. Suchsleeves divided in mat-like manner into small “partial cushions” caneither be segmented by punctiform connections or provided with net-likestructures in the interior in order to prevent floating of the ice.

It is also possible to “sew” in fixed manner into a sleeve an extensionvolume, e.g. in the form of a gas or air-filled body or a compressiblematerial, e.g. foam rubber. However, it must be borne in mind thatfloating ice must not vary the orientation of the extension member andthat also in the case of repeated partial discharging the resiliency ofsaid expansion volume must be sufficiently high in order to in each caserestore the original volume.

Having thus described the invention, what is claimed and desired to besecured by Letters Patent is:
 1. A cooling apparatus for conditioningair within an area of a vehicle, the air within the vehicle area capableof being substantially isolated from surrounding ambient air, thecooling apparatus capable of retaining a fluid in a melted liquid stateor frozen solid state, the cooling apparatus comprising: a) a closedcontainer for retaining the fluid, the container comprising an outerelastic sleeve and an internal volume, the elastic sleeve permitting thecontainer to expand, or contract in response to fluctuations in thecontainer internal volume; b) a jacket member inserted around theelastic sleeve for stabilizing the container in a generally fixedposition, the jacket member having an inner and outer surface; c) meansfor manipulating the temperature of the container fluid, the means inthermal contact with the fluid; and d) means for reducing expansion ofthe container elastic sleeve when the container fluid is in the frozensolid state, the means inserted within the container.
 2. The coolingapparatus of claim 1, wherein the jacket member has a plurality of ribsformed along the outer surface for increasing heat transfer propertiesof the jacket member.
 3. The cooling apparatus of claim 1, wherein thejacket member is circular and has a slot formed therein permitting thejacket member to deform as the elastic sleeve expands or contracts inresponse to fluctuations in the container internal volume.
 4. Thecooling apparatus of claim 1, wherein the jacket member comprises aplurality of segments surrounding the elastic sleeve, each segmentattached to an adjacent segment by a clamp.
 5. The cooling apparatus ofclaim 4, wherein a small gap is provided between each adjacent jacketmember segment.
 6. The cooling apparatus of claim 1, wherein the meansfor manipulating the temperature of the container fluid comprises atleast one pipe capable of carrying fluid or a gas.
 7. The coolingapparatus of claim 6, wherein a pair of pipes are employed.
 8. Thecooling apparatus of claim 7, wherein one of each of the pair of pipesare attached juxtaposed in thermal contact to the jacket member outersurface at opposed sides.
 9. The cooling apparatus of claim 7, whereinone of each of the pair of pipes are attached juxtaposed in thermalcontact to an inner surface of the elastic sleeve at opposed sideswithin the container.
 10. The cooling apparatus of claim 7, wherein asingle pipe is employed within the container along a center axisthereof.
 11. The cooling apparatus of claim 1, wherein the elasticsleeve comprises a cushion-shaped member having at least one pocketformed therein for receiving the means for manipulating the temperatureof the container fluid.
 12. The cooling apparatus of claim 1, whereinthe elastic sleeve comprises a cushion-shaped member having a pluralityof sections formed by a plurality of transversely disposed seams. 13.The cooling apparatus of claim 1, wherein the container comprises aplurality of chambers, each chamber comprising a portion of a total ofthe container internal volume.
 14. The cooling apparatus of claim 1,wherein the means for reducing expansion of the container elastic sleevewhen the container fluid is in the frozen solid state is at least onecapsule having a closed outer surface and an internal cavity, the atleast one capsule disposed within the container fluid.
 15. The coolingapparatus of claim 14, wherein the at least one capsule contains fluidwithin the capsule internal cavity, the fluid within the capsuleinternal cavity having a freezing point threshold below that of thecontainer fluid.
 16. The cooling apparatus of claim 14, wherein the atleast one capsule contains a gas within the capsule internal cavity. 17.The cooling apparatus of claim 14, wherein the at least one capsulecomprises a spring inserted within the internal cavity permitting thecapsule to return to a relaxed state after being deformed in a depressedstate.
 18. The cooling apparatus of claim 14, wherein the at least onecapsule is dumbbell-shaped.
 19. The cooling apparatus of claim 1,wherein the container fluid is water.
 20. A cooling apparatus forconditioning air within an area of a vehicle, the air within the vehiclearea capable of being substantially isolated from surrounding ambientair, the cooling apparatus capable of retaining a fluid in a meltedliquid state or frozen solid state, the cooling apparatus comprising: a)a closed container for retaining the fluid, the container comprising anelastic outer sleeve and an internal volume, the elastic sleevepermitting the container to expand or contract in response tofluctuations in the container internal volume; b) a jacket memberinserted around the elastic sleeve for stabilizing the container in agenerally fixed position, the jacket member having an inner and outersurface; c) at least one pipe capable of carrying a gas or fluid formanipulating the temperature of the container fluid, the at least onepipe in thermal contact with the fluid; and d) at least one capsulehaving a closed outer surface and an internal cavity, the at least onecapsule disposed within the container fluid and capable of deforming inresponse to the container fluid changing from a melted liquid state to afrozen solid state.